Cellucity refuse to change wiring despite selling me the wrong item

I went to Cellucity at Benmore Gardens to purchase a Iphone charger. I bought one but made the mistake of not checking the contents in the box. When I opened it at home the wiring was not for an iphone charger. I went back to the store three days later to change it and the person servicing me refused to change and said it was not their wiring, despite my contention that I had opened a new box. The manager was no more helpful and did not even venture out of the back office to talk to me. Very disappointed with the service and will never use the store again .